硫酸氢钠催化合成丁酸丁酯的研究

硫酸氢钠是催化丁酸与丁醇酯化反应的良好催化剂，其最佳反应条件为：催化剂用量为O．2g／0．1mol丁酸，酸醇摩尔比为1：3，反应时间1．5h，丁酸的酯化率可达99％．该催化剂催化效果好，使用量少，酯化率高，三废排放少，廉价易得，极有应用价值．     

硫酸氢钠催化合成丁酸苄酯

研究了以硫酸氢钠为催化剂，丁酸和苄醇为原料合成丁酸苄酯，考察了影响酯化率的各种因素，确定了最佳反应条件为：丁酸用量0．1mol时，苄醇与丁酸的物质的量比为1．2，0．5g催化剂，10mL甲苯作带水剂，反应时间40min，酯化率98％以上．结果表明：硫酸氢钠是合成丁酸苄酯的优良催化剂．     

硫酸氢钠作为合成己酸异戊酯催化剂的研究

利用硫酸氢钠作为酯化反应催化剂合成了己酸异戊酯，确定了其最佳反应条件为：催化剂用量为0．2g／0．1mol己酸，醇酸物质的量比为1．5：1，带水剂环己烷10mL，回流反应时间1．5h，己酸的酯化率可达99．39％。实验表明该催化剂催化效果好，使用量少，酯化率高，环境污染小，廉价易得，很有应用价值。     

硫酸氢钠催化及分子筛脱水合成己酸乙酯的研究

利用硫酸氢钠作为酯化反应催化剂合成了己酸乙酯，确定了其最佳反应条件——催化剂用量为每0．1mol己酸0．3克，醇酸物质的量比为2．5：1，以3A分子筛为脱水剂，回流反应时问为3．5h，己酸的酯化率可达98．69％．实验表明：该催化剂催化效果好，使用量少，酯化率高，环境污染小，廉价易得，用3A分子筛脱水，操作简便，较有工业应用价值．     

氨基磺酸催化合成苯甲酸正丁酯的研究

以氨基磺酸为催化剂，催化合成了苯甲酸正丁酯，用正交实验法确定了反应的最佳条件．最佳条件为：催化剂用量为0.6g／0．1mol苯甲酸，醇酸物质的量比为2：1；回流时间为3．5—4．0h；苯甲酸的酯化率可达97．26％．该催化剂催化效果好，用量少，酯化率高，污染小，有一定的工业应用价值．     

硫酸氢钠催化合成丁酸戊酯

以正丁酸和戊醇为原料，硫酸氢钠为催化剂合成了丁酸戊酯．最佳合成条件：以0．1mol正丁酸为基准，醇酸摩尔比为1．2：1，催化剂用量0．2克，甲苯5毫升，反应时间30min，丁酸的酯化率可达99．3％，在无甲苯存在下，合成食品级丁酸戊酯，酯化率可达99．7％．     

硫酸氢钠催化合成丁酸丁酯

以硫酸氢钠为催化剂催化正丁酸和正丁醇进行酯化反应合成了丁酸丁酯 ,讨论了反应时间、催化剂用量、酸醇摩尔比等因素对酯化率的影响 ,确定了最佳反应条件 :酸醇摩尔比 1∶1 1,催化剂用量 0 1g ,反应时间6 0min ,反应温度 12 0～ 14 0℃ ,酯化率达 98 8% .     

硫酸铜催化合成癸二酸二丁酯的研究

利用硫酸铜作为酯化反应催化剂合成了癸二酸二丁酯，其最佳反应条件为：催化剂用量3．0g/0．05mol癸二酸，醇酸摩尔比为4，反应时间3．0h，带水剂12ml，癸二酸的酯化率可达97．23％，该催化剂催化效果好，使用量少，酯化率高，可重复使用，无环境污染，价廉易得，是一种极有应用价值的催化剂。     

固体超强酸ZrO2-SO2-4催化合成丁酸异丁酯

以正丁酸和异丁醇为原料，固体超强酸ZrO2-SO4^2-为催化剂，催化合成丁酸异丁酯．探讨了原料醇酸摩尔比、温度、时间、催化剂用量和重复使用性等工艺条件对酯化反应的影响、实验结果表明，在最佳工艺条件下酯化率可达98％以上．     

复合固体超强酸SO4^2-／ZrO2-Ce2O3的制备及催化合成丁酸异戊酯的研究

合成了复合固体超强酸SO4^2-／ZrO2-Ce2O3,研究了Ce2O3的最佳添加量,并将其应用于催化合成丁酸异戊酯的反应,探索到了最佳反应条件．Ce2O3的最佳添加量为2．0％,最佳反应条件为0．10mol丁酸使用1．0g复合固体超强酸催化剂,醇酸摩尔比2．0,反应时间为2．5h,丁酸的酯化率可达96％以上,并且不污染环境．     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.